Welcome to the SeeMeCNC Community

I've got my Rostock set up (well, my brother's), and printing away. I notice something though. Whatever I print is about 5% smaller than it should be in the X and Y directions. The Z height, thickness of the part off the bed, is always right. But the part will be around 5% shorter and narrower in the other two directions then it is supposed to be.

I don't see anything in the manual about calibrating in this way. What could be causing this? In the Matter Control software, the dimensions of the part show correctly, but what prints out is the wrong size except for the thickness off the bed.

Thoughts appreciated.

Brian

That would be diagonal rod length.

(Observed size / Specified size) * Current arm length setting = New arm length should get you a working arm length. It's likely a small hiccup in the assembly making it act slightly different. Not anything I know how to fix the source of, but we can nail the symptom (It may also be your arms were off the expected shrinkage curve somewhat)

Sorry for the delayed response. Thank you! This worked beautifully. In the end, I figured out that what happened was I downloaded the new firmware, but we have the old arms. So the arm length was for the new spring loaded carriages. Feel like I should have seen that coming.

-Brian

I try to be helpful when I can. Glad it worked for you.